net/sctp/sm_sideeffect.c

   1 /* SCTP kernel implementation
   2  * (C) Copyright IBM Corp. 2001, 2004
   3  * Copyright (c) 1999 Cisco, Inc.
   4  * Copyright (c) 1999-2001 Motorola, Inc.
   5  *
   6  * This file is part of the SCTP kernel implementation
   7  *
   8  * These functions work with the state functions in sctp_sm_statefuns.c
   9  * to implement that state operations.  These functions implement the
  10  * steps which require modifying existing data structures.
  11  *
  12  * This SCTP implementation is free software;
  13  * you can redistribute it and/or modify it under the terms of
  14  * the GNU General Public License as published by
  15  * the Free Software Foundation; either version 2, or (at your option)
  16  * any later version.
  17  *
  18  * This SCTP implementation is distributed in the hope that it
  19  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  20  *                 ************************
  21  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  22  * See the GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with GNU CC; see the file COPYING.  If not, write to
  26  * the Free Software Foundation, 59 Temple Place - Suite 330,
  27  * Boston, MA 02111-1307, USA.
  28  *
  29  * Please send any bug reports or fixes you make to the
  30  * email address(es):
  31  *    lksctp developers <lksctp-developers@lists.sourceforge.net>
  32  *
  33  * Or submit a bug report through the following website:
  34  *    http://www.sf.net/projects/lksctp
  35  *
  36  * Written or modified by:
  37  *    La Monte H.P. Yarroll <piggy@acm.org>
  38  *    Karl Knutson          <karl@athena.chicago.il.us>
  39  *    Jon Grimm             <jgrimm@austin.ibm.com>
  40  *    Hui Huang             <hui.huang@nokia.com>
  41  *    Dajiang Zhang         <dajiang.zhang@nokia.com>
  42  *    Daisy Chang           <daisyc@us.ibm.com>
  43  *    Sridhar Samudrala     <sri@us.ibm.com>
  44  *    Ardelle Fan           <ardelle.fan@intel.com>
  45  *
  46  * Any bugs reported given to us we will try to fix... any fixes shared will
  47  * be incorporated into the next SCTP release.
  48  */
  49
  50 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  51
  52 #include <linux/skbuff.h>
  53 #include <linux/types.h>
  54 #include <linux/socket.h>
  55 #include <linux/ip.h>
  56 #include <linux/gfp.h>
  57 #include <net/sock.h>
  58 #include <net/sctp/sctp.h>
  59 #include <net/sctp/sm.h>
  60
  61 static int sctp_cmd_interpreter(sctp_event_t event_type,
  62                                 sctp_subtype_t subtype,
  63                                 sctp_state_t state,
  64                                 struct sctp_endpoint *ep,
  65                                 struct sctp_association *asoc,
  66                                 void *event_arg,
  67                                 sctp_disposition_t status,
  68                                 sctp_cmd_seq_t *commands,
  69                                 gfp_t gfp);
  70 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
  71                              sctp_state_t state,
  72                              struct sctp_endpoint *ep,
  73                              struct sctp_association *asoc,
  74                              void *event_arg,
  75                              sctp_disposition_t status,
  76                              sctp_cmd_seq_t *commands,
  77                              gfp_t gfp);
  78
  79 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
  80                                      struct sctp_transport *t);
  81 /********************************************************************
  82  * Helper functions
  83  ********************************************************************/
  84
  85 /* A helper function for delayed processing of INET ECN CE bit. */
  86 static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
  87                                 __u32 lowest_tsn)
  88 {
  89         /* Save the TSN away for comparison when we receive CWR */
  90
  91         asoc->last_ecne_tsn = lowest_tsn;
  92         asoc->need_ecne = 1;
  93 }
  94
  95 /* Helper function for delayed processing of SCTP ECNE chunk.  */
  96 /* RFC 2960 Appendix A
  97  *
  98  * RFC 2481 details a specific bit for a sender to send in
  99  * the header of its next outbound TCP segment to indicate to
 100  * its peer that it has reduced its congestion window.  This
 101  * is termed the CWR bit.  For SCTP the same indication is made
 102  * by including the CWR chunk.  This chunk contains one data
 103  * element, i.e. the TSN number that was sent in the ECNE chunk.
 104  * This element represents the lowest TSN number in the datagram
 105  * that was originally marked with the CE bit.
 106  */
 107 static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
 108                                            __u32 lowest_tsn,
 109                                            struct sctp_chunk *chunk)
 110 {
 111         struct sctp_chunk *repl;
 112
 113         /* Our previously transmitted packet ran into some congestion
 114          * so we should take action by reducing cwnd and ssthresh
 115          * and then ACK our peer that we we've done so by
 116          * sending a CWR.
 117          */
 118
 119         /* First, try to determine if we want to actually lower
 120          * our cwnd variables.  Only lower them if the ECNE looks more
 121          * recent than the last response.
 122          */
 123         if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
 124                 struct sctp_transport *transport;
 125
 126                 /* Find which transport's congestion variables
 127                  * need to be adjusted.
 128                  */
 129                 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
 130
 131                 /* Update the congestion variables. */
 132                 if (transport)
 133                         sctp_transport_lower_cwnd(transport,
 134                                                   SCTP_LOWER_CWND_ECNE);
 135                 asoc->last_cwr_tsn = lowest_tsn;
 136         }
 137
 138         /* Always try to quiet the other end.  In case of lost CWR,
 139          * resend last_cwr_tsn.
 140          */
 141         repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
 142
 143         /* If we run out of memory, it will look like a lost CWR.  We'll
 144          * get back in sync eventually.
 145          */
 146         return repl;
 147 }
 148
 149 /* Helper function to do delayed processing of ECN CWR chunk.  */
 150 static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
 151                                  __u32 lowest_tsn)
 152 {
 153         /* Turn off ECNE getting auto-prepended to every outgoing
 154          * packet
 155          */
 156         asoc->need_ecne = 0;
 157 }
 158
 159 /* Generate SACK if necessary.  We call this at the end of a packet.  */
 160 static int sctp_gen_sack(struct sctp_association *asoc, int force,
 161                          sctp_cmd_seq_t *commands)
 162 {
 163         __u32 ctsn, max_tsn_seen;
 164         struct sctp_chunk *sack;
 165         struct sctp_transport *trans = asoc->peer.last_data_from;
 166         int error = 0;
 167
 168         if (force ||
 169             (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
 170             (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
 171                 asoc->peer.sack_needed = 1;
 172
 173         ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
 174         max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
 175
 176         /* From 12.2 Parameters necessary per association (i.e. the TCB):
 177          *
 178          * Ack State : This flag indicates if the next received packet
 179          *           : is to be responded to with a SACK. ...
 180          *           : When DATA chunks are out of order, SACK's
 181          *           : are not delayed (see Section 6).
 182          *
 183          * [This is actually not mentioned in Section 6, but we
 184          * implement it here anyway. --piggy]
 185          */
 186         if (max_tsn_seen != ctsn)
 187                 asoc->peer.sack_needed = 1;
 188
 189         /* From 6.2  Acknowledgement on Reception of DATA Chunks:
 190          *
 191          * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
 192          * an acknowledgement SHOULD be generated for at least every
 193          * second packet (not every second DATA chunk) received, and
 194          * SHOULD be generated within 200 ms of the arrival of any
 195          * unacknowledged DATA chunk. ...
 196          */
 197         if (!asoc->peer.sack_needed) {
 198                 asoc->peer.sack_cnt++;
 199
 200                 /* Set the SACK delay timeout based on the
 201                  * SACK delay for the last transport
 202                  * data was received from, or the default
 203                  * for the association.
 204                  */
 205                 if (trans) {
 206                         /* We will need a SACK for the next packet.  */
 207                         if (asoc->peer.sack_cnt >= trans->sackfreq - 1)
 208                                 asoc->peer.sack_needed = 1;
 209
 210                         asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 211                                 trans->sackdelay;
 212                 } else {
 213                         /* We will need a SACK for the next packet.  */
 214                         if (asoc->peer.sack_cnt >= asoc->sackfreq - 1)
 215                                 asoc->peer.sack_needed = 1;
 216
 217                         asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 218                                 asoc->sackdelay;
 219                 }
 220
 221                 /* Restart the SACK timer. */
 222                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
 223                                 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 224         } else {
 225                 asoc->a_rwnd = asoc->rwnd;
 226                 sack = sctp_make_sack(asoc);
 227                 if (!sack)
 228                         goto nomem;
 229
 230                 asoc->peer.sack_needed = 0;
 231                 asoc->peer.sack_cnt = 0;
 232
 233                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
 234
 235                 /* Stop the SACK timer.  */
 236                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
 237                                 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 238         }
 239
 240         return error;
 241 nomem:
 242         error = -ENOMEM;
 243         return error;
 244 }
 245
 246 /* When the T3-RTX timer expires, it calls this function to create the
 247  * relevant state machine event.
 248  */
 249 void sctp_generate_t3_rtx_event(unsigned long peer)
 250 {
 251         int error;
 252         struct sctp_transport *transport = (struct sctp_transport *) peer;
 253         struct sctp_association *asoc = transport->asoc;
 254         struct net *net = sock_net(asoc->base.sk);
 255
 256         /* Check whether a task is in the sock.  */
 257
 258         sctp_bh_lock_sock(asoc->base.sk);
 259         if (sock_owned_by_user(asoc->base.sk)) {
 260                 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
 261
 262                 /* Try again later.  */
 263                 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
 264                         sctp_transport_hold(transport);
 265                 goto out_unlock;
 266         }
 267
 268         /* Is this transport really dead and just waiting around for
 269          * the timer to let go of the reference?
 270          */
 271         if (transport->dead)
 272                 goto out_unlock;
 273
 274         /* Run through the state machine.  */
 275         error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
 276                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
 277                            asoc->state,
 278                            asoc->ep, asoc,
 279                            transport, GFP_ATOMIC);
 280
 281         if (error)
 282                 asoc->base.sk->sk_err = -error;
 283
 284 out_unlock:
 285         sctp_bh_unlock_sock(asoc->base.sk);
 286         sctp_transport_put(transport);
 287 }
 288
 289 /* This is a sa interface for producing timeout events.  It works
 290  * for timeouts which use the association as their parameter.
 291  */
 292 static void sctp_generate_timeout_event(struct sctp_association *asoc,
 293                                         sctp_event_timeout_t timeout_type)
 294 {
 295         struct net *net = sock_net(asoc->base.sk);
 296         int error = 0;
 297
 298         sctp_bh_lock_sock(asoc->base.sk);
 299         if (sock_owned_by_user(asoc->base.sk)) {
 300                 SCTP_DEBUG_PRINTK("%s:Sock is busy: timer %d\n",
 301                                   __func__,
 302                                   timeout_type);
 303
 304                 /* Try again later.  */
 305                 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
 306                         sctp_association_hold(asoc);
 307                 goto out_unlock;
 308         }
 309
 310         /* Is this association really dead and just waiting around for
 311          * the timer to let go of the reference?
 312          */
 313         if (asoc->base.dead)
 314                 goto out_unlock;
 315
 316         /* Run through the state machine.  */
 317         error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
 318                            SCTP_ST_TIMEOUT(timeout_type),
 319                            asoc->state, asoc->ep, asoc,
 320                            (void *)timeout_type, GFP_ATOMIC);
 321
 322         if (error)
 323                 asoc->base.sk->sk_err = -error;
 324
 325 out_unlock:
 326         sctp_bh_unlock_sock(asoc->base.sk);
 327         sctp_association_put(asoc);
 328 }
 329
 330 static void sctp_generate_t1_cookie_event(unsigned long data)
 331 {
 332         struct sctp_association *asoc = (struct sctp_association *) data;
 333         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
 334 }
 335
 336 static void sctp_generate_t1_init_event(unsigned long data)
 337 {
 338         struct sctp_association *asoc = (struct sctp_association *) data;
 339         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
 340 }
 341
 342 static void sctp_generate_t2_shutdown_event(unsigned long data)
 343 {
 344         struct sctp_association *asoc = (struct sctp_association *) data;
 345         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
 346 }
 347
 348 static void sctp_generate_t4_rto_event(unsigned long data)
 349 {
 350         struct sctp_association *asoc = (struct sctp_association *) data;
 351         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
 352 }
 353
 354 static void sctp_generate_t5_shutdown_guard_event(unsigned long data)
 355 {
 356         struct sctp_association *asoc = (struct sctp_association *)data;
 357         sctp_generate_timeout_event(asoc,
 358                                     SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
 359
 360 } /* sctp_generate_t5_shutdown_guard_event() */
 361
 362 static void sctp_generate_autoclose_event(unsigned long data)
 363 {
 364         struct sctp_association *asoc = (struct sctp_association *) data;
 365         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
 366 }
 367
 368 /* Generate a heart beat event.  If the sock is busy, reschedule.   Make
 369  * sure that the transport is still valid.
 370  */
 371 void sctp_generate_heartbeat_event(unsigned long data)
 372 {
 373         int error = 0;
 374         struct sctp_transport *transport = (struct sctp_transport *) data;
 375         struct sctp_association *asoc = transport->asoc;
 376         struct net *net = sock_net(asoc->base.sk);
 377
 378         sctp_bh_lock_sock(asoc->base.sk);
 379         if (sock_owned_by_user(asoc->base.sk)) {
 380                 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
 381
 382                 /* Try again later.  */
 383                 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
 384                         sctp_transport_hold(transport);
 385                 goto out_unlock;
 386         }
 387
 388         /* Is this structure just waiting around for us to actually
 389          * get destroyed?
 390          */
 391         if (transport->dead)
 392                 goto out_unlock;
 393
 394         error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
 395                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
 396                            asoc->state, asoc->ep, asoc,
 397                            transport, GFP_ATOMIC);
 398
 399          if (error)
 400                  asoc->base.sk->sk_err = -error;
 401
 402 out_unlock:
 403         sctp_bh_unlock_sock(asoc->base.sk);
 404         sctp_transport_put(transport);
 405 }
 406
 407 /* Handle the timeout of the ICMP protocol unreachable timer.  Trigger
 408  * the correct state machine transition that will close the association.
 409  */
 410 void sctp_generate_proto_unreach_event(unsigned long data)
 411 {
 412         struct sctp_transport *transport = (struct sctp_transport *) data;
 413         struct sctp_association *asoc = transport->asoc;
 414         struct net *net = sock_net(asoc->base.sk);
 415
 416         sctp_bh_lock_sock(asoc->base.sk);
 417         if (sock_owned_by_user(asoc->base.sk)) {
 418                 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
 419
 420                 /* Try again later.  */
 421                 if (!mod_timer(&transport->proto_unreach_timer,
 422                                 jiffies + (HZ/20)))
 423                         sctp_association_hold(asoc);
 424                 goto out_unlock;
 425         }
 426
 427         /* Is this structure just waiting around for us to actually
 428          * get destroyed?
 429          */
 430         if (asoc->base.dead)
 431                 goto out_unlock;
 432
 433         sctp_do_sm(net, SCTP_EVENT_T_OTHER,
 434                    SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
 435                    asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC);
 436
 437 out_unlock:
 438         sctp_bh_unlock_sock(asoc->base.sk);
 439         sctp_association_put(asoc);
 440 }
 441
 442
 443 /* Inject a SACK Timeout event into the state machine.  */
 444 static void sctp_generate_sack_event(unsigned long data)
 445 {
 446         struct sctp_association *asoc = (struct sctp_association *) data;
 447         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
 448 }
 449
 450 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
 451         NULL,
 452         sctp_generate_t1_cookie_event,
 453         sctp_generate_t1_init_event,
 454         sctp_generate_t2_shutdown_event,
 455         NULL,
 456         sctp_generate_t4_rto_event,
 457         sctp_generate_t5_shutdown_guard_event,
 458         NULL,
 459         sctp_generate_sack_event,
 460         sctp_generate_autoclose_event,
 461 };
 462
 463
 464 /* RFC 2960 8.2 Path Failure Detection
 465  *
 466  * When its peer endpoint is multi-homed, an endpoint should keep a
 467  * error counter for each of the destination transport addresses of the
 468  * peer endpoint.
 469  *
 470  * Each time the T3-rtx timer expires on any address, or when a
 471  * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
 472  * the error counter of that destination address will be incremented.
 473  * When the value in the error counter exceeds the protocol parameter
 474  * 'Path.Max.Retrans' of that destination address, the endpoint should
 475  * mark the destination transport address as inactive, and a
 476  * notification SHOULD be sent to the upper layer.
 477  *
 478  */
 479 static void sctp_do_8_2_transport_strike(sctp_cmd_seq_t *commands,
 480                                          struct sctp_association *asoc,
 481                                          struct sctp_transport *transport,
 482                                          int is_hb)
 483 {
 484         /* The check for association's overall error counter exceeding the
 485          * threshold is done in the state function.
 486          */
 487         /* We are here due to a timer expiration.  If the timer was
 488          * not a HEARTBEAT, then normal error tracking is done.
 489          * If the timer was a heartbeat, we only increment error counts
 490          * when we already have an outstanding HEARTBEAT that has not
 491          * been acknowledged.
 492          * Additionally, some tranport states inhibit error increments.
 493          */
 494         if (!is_hb) {
 495                 asoc->overall_error_count++;
 496                 if (transport->state != SCTP_INACTIVE)
 497                         transport->error_count++;
 498          } else if (transport->hb_sent) {
 499                 if (transport->state != SCTP_UNCONFIRMED)
 500                         asoc->overall_error_count++;
 501                 if (transport->state != SCTP_INACTIVE)
 502                         transport->error_count++;
 503         }
 504
 505         /* If the transport error count is greater than the pf_retrans
 506          * threshold, and less than pathmaxrtx, then mark this transport
 507          * as Partially Failed, ee SCTP Quick Failover Draft, secon 5.1,
 508          * point 1
 509          */
 510         if ((transport->state != SCTP_PF) &&
 511            (asoc->pf_retrans < transport->pathmaxrxt) &&
 512            (transport->error_count > asoc->pf_retrans)) {
 513
 514                 sctp_assoc_control_transport(asoc, transport,
 515                                              SCTP_TRANSPORT_PF,
 516                                              0);
 517
 518                 /* Update the hb timer to resend a heartbeat every rto */
 519                 sctp_cmd_hb_timer_update(commands, transport);
 520         }
 521
 522         if (transport->state != SCTP_INACTIVE &&
 523             (transport->error_count > transport->pathmaxrxt)) {
 524                 SCTP_DEBUG_PRINTK_IPADDR("transport_strike:association %p",
 525                                          " transport IP: port:%d failed.\n",
 526                                          asoc,
 527                                          (&transport->ipaddr),
 528                                          ntohs(transport->ipaddr.v4.sin_port));
 529                 sctp_assoc_control_transport(asoc, transport,
 530                                              SCTP_TRANSPORT_DOWN,
 531                                              SCTP_FAILED_THRESHOLD);
 532         }
 533
 534         /* E2) For the destination address for which the timer
 535          * expires, set RTO <- RTO * 2 ("back off the timer").  The
 536          * maximum value discussed in rule C7 above (RTO.max) may be
 537          * used to provide an upper bound to this doubling operation.
 538          *
 539          * Special Case:  the first HB doesn't trigger exponential backoff.
 540          * The first unacknowledged HB triggers it.  We do this with a flag
 541          * that indicates that we have an outstanding HB.
 542          */
 543         if (!is_hb || transport->hb_sent) {
 544                 transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
 545         }
 546 }
 547
 548 /* Worker routine to handle INIT command failure.  */
 549 static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
 550                                  struct sctp_association *asoc,
 551                                  unsigned int error)
 552 {
 553         struct sctp_ulpevent *event;
 554
 555         event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
 556                                                 (__u16)error, 0, 0, NULL,
 557                                                 GFP_ATOMIC);
 558
 559         if (event)
 560                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 561                                 SCTP_ULPEVENT(event));
 562
 563         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 564                         SCTP_STATE(SCTP_STATE_CLOSED));
 565
 566         /* SEND_FAILED sent later when cleaning up the association. */
 567         asoc->outqueue.error = error;
 568         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 569 }
 570
 571 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
 572 static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
 573                                   struct sctp_association *asoc,
 574                                   sctp_event_t event_type,
 575                                   sctp_subtype_t subtype,
 576                                   struct sctp_chunk *chunk,
 577                                   unsigned int error)
 578 {
 579         struct sctp_ulpevent *event;
 580
 581         /* Cancel any partial delivery in progress. */
 582         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
 583
 584         if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
 585                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 586                                                 (__u16)error, 0, 0, chunk,
 587                                                 GFP_ATOMIC);
 588         else
 589                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 590                                                 (__u16)error, 0, 0, NULL,
 591                                                 GFP_ATOMIC);
 592         if (event)
 593                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 594                                 SCTP_ULPEVENT(event));
 595
 596         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 597                         SCTP_STATE(SCTP_STATE_CLOSED));
 598
 599         /* SEND_FAILED sent later when cleaning up the association. */
 600         asoc->outqueue.error = error;
 601         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 602 }
 603
 604 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
 605  * inside the cookie.  In reality, this is only used for INIT-ACK processing
 606  * since all other cases use "temporary" associations and can do all
 607  * their work in statefuns directly.
 608  */
 609 static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
 610                                  struct sctp_association *asoc,
 611                                  struct sctp_chunk *chunk,
 612                                  sctp_init_chunk_t *peer_init,
 613                                  gfp_t gfp)
 614 {
 615         int error;
 616
 617         /* We only process the init as a sideeffect in a single
 618          * case.   This is when we process the INIT-ACK.   If we
 619          * fail during INIT processing (due to malloc problems),
 620          * just return the error and stop processing the stack.
 621          */
 622         if (!sctp_process_init(asoc, chunk, sctp_source(chunk), peer_init, gfp))
 623                 error = -ENOMEM;
 624         else
 625                 error = 0;
 626
 627         return error;
 628 }
 629
 630 /* Helper function to break out starting up of heartbeat timers.  */
 631 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
 632                                      struct sctp_association *asoc)
 633 {
 634         struct sctp_transport *t;
 635
 636         /* Start a heartbeat timer for each transport on the association.
 637          * hold a reference on the transport to make sure none of
 638          * the needed data structures go away.
 639          */
 640         list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) {
 641
 642                 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 643                         sctp_transport_hold(t);
 644         }
 645 }
 646
 647 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
 648                                     struct sctp_association *asoc)
 649 {
 650         struct sctp_transport *t;
 651
 652         /* Stop all heartbeat timers. */
 653
 654         list_for_each_entry(t, &asoc->peer.transport_addr_list,
 655                         transports) {
 656                 if (del_timer(&t->hb_timer))
 657                         sctp_transport_put(t);
 658         }
 659 }
 660
 661 /* Helper function to stop any pending T3-RTX timers */
 662 static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
 663                                         struct sctp_association *asoc)
 664 {
 665         struct sctp_transport *t;
 666
 667         list_for_each_entry(t, &asoc->peer.transport_addr_list,
 668                         transports) {
 669                 if (timer_pending(&t->T3_rtx_timer) &&
 670                     del_timer(&t->T3_rtx_timer)) {
 671                         sctp_transport_put(t);
 672                 }
 673         }
 674 }
 675
 676
 677 /* Helper function to update the heartbeat timer. */
 678 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
 679                                      struct sctp_transport *t)
 680 {
 681         /* Update the heartbeat timer.  */
 682         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 683                 sctp_transport_hold(t);
 684 }
 685
 686 /* Helper function to handle the reception of an HEARTBEAT ACK.  */
 687 static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
 688                                   struct sctp_association *asoc,
 689                                   struct sctp_transport *t,
 690                                   struct sctp_chunk *chunk)
 691 {
 692         sctp_sender_hb_info_t *hbinfo;
 693         int was_unconfirmed = 0;
 694
 695         /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
 696          * HEARTBEAT should clear the error counter of the destination
 697          * transport address to which the HEARTBEAT was sent.
 698          */
 699         t->error_count = 0;
 700
 701         /*
 702          * Although RFC4960 specifies that the overall error count must
 703          * be cleared when a HEARTBEAT ACK is received, we make an
 704          * exception while in SHUTDOWN PENDING. If the peer keeps its
 705          * window shut forever, we may never be able to transmit our
 706          * outstanding data and rely on the retransmission limit be reached
 707          * to shutdown the association.
 708          */
 709         if (t->asoc->state != SCTP_STATE_SHUTDOWN_PENDING)
 710                 t->asoc->overall_error_count = 0;
 711
 712         /* Clear the hb_sent flag to signal that we had a good
 713          * acknowledgement.
 714          */
 715         t->hb_sent = 0;
 716
 717         /* Mark the destination transport address as active if it is not so
 718          * marked.
 719          */
 720         if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED)) {
 721                 was_unconfirmed = 1;
 722                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 723                                              SCTP_HEARTBEAT_SUCCESS);
 724         }
 725
 726         if (t->state == SCTP_PF)
 727                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 728                                              SCTP_HEARTBEAT_SUCCESS);
 729
 730         /* The receiver of the HEARTBEAT ACK should also perform an
 731          * RTT measurement for that destination transport address
 732          * using the time value carried in the HEARTBEAT ACK chunk.
 733          * If the transport's rto_pending variable has been cleared,
 734          * it was most likely due to a retransmit.  However, we want
 735          * to re-enable it to properly update the rto.
 736          */
 737         if (t->rto_pending == 0)
 738                 t->rto_pending = 1;
 739
 740         hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
 741         sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
 742
 743         /* Update the heartbeat timer.  */
 744         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 745                 sctp_transport_hold(t);
 746
 747         if (was_unconfirmed && asoc->peer.transport_count == 1)
 748                 sctp_transport_immediate_rtx(t);
 749 }
 750
 751
 752 /* Helper function to process the process SACK command.  */
 753 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
 754                                  struct sctp_association *asoc,
 755                                  struct sctp_chunk *chunk)
 756 {
 757         int err = 0;
 758
 759         if (sctp_outq_sack(&asoc->outqueue, chunk)) {
 760                 struct net *net = sock_net(asoc->base.sk);
 761
 762                 /* There are no more TSNs awaiting SACK.  */
 763                 err = sctp_do_sm(net, SCTP_EVENT_T_OTHER,
 764                                  SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
 765                                  asoc->state, asoc->ep, asoc, NULL,
 766                                  GFP_ATOMIC);
 767         }
 768
 769         return err;
 770 }
 771
 772 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
 773  * the transport for a shutdown chunk.
 774  */
 775 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
 776                               struct sctp_association *asoc,
 777                               struct sctp_chunk *chunk)
 778 {
 779         struct sctp_transport *t;
 780
 781         if (chunk->transport)
 782                 t = chunk->transport;
 783         else {
 784                 t = sctp_assoc_choose_alter_transport(asoc,
 785                                               asoc->shutdown_last_sent_to);
 786                 chunk->transport = t;
 787         }
 788         asoc->shutdown_last_sent_to = t;
 789         asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
 790 }
 791
 792 /* Helper function to change the state of an association. */
 793 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
 794                                struct sctp_association *asoc,
 795                                sctp_state_t state)
 796 {
 797         struct sock *sk = asoc->base.sk;
 798
 799         asoc->state = state;
 800
 801         SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n",
 802                           asoc, sctp_state_tbl[state]);
 803
 804         if (sctp_style(sk, TCP)) {
 805                 /* Change the sk->sk_state of a TCP-style socket that has
 806                  * successfully completed a connect() call.
 807                  */
 808                 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
 809                         sk->sk_state = SCTP_SS_ESTABLISHED;
 810
 811                 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
 812                 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
 813                     sctp_sstate(sk, ESTABLISHED))
 814                         sk->sk_shutdown |= RCV_SHUTDOWN;
 815         }
 816
 817         if (sctp_state(asoc, COOKIE_WAIT)) {
 818                 /* Reset init timeouts since they may have been
 819                  * increased due to timer expirations.
 820                  */
 821                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
 822                                                 asoc->rto_initial;
 823                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
 824                                                 asoc->rto_initial;
 825         }
 826
 827         if (sctp_state(asoc, ESTABLISHED) ||
 828             sctp_state(asoc, CLOSED) ||
 829             sctp_state(asoc, SHUTDOWN_RECEIVED)) {
 830                 /* Wake up any processes waiting in the asoc's wait queue in
 831                  * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
 832                  */
 833                 if (waitqueue_active(&asoc->wait))
 834                         wake_up_interruptible(&asoc->wait);
 835
 836                 /* Wake up any processes waiting in the sk's sleep queue of
 837                  * a TCP-style or UDP-style peeled-off socket in
 838                  * sctp_wait_for_accept() or sctp_wait_for_packet().
 839                  * For a UDP-style socket, the waiters are woken up by the
 840                  * notifications.
 841                  */
 842                 if (!sctp_style(sk, UDP))
 843                         sk->sk_state_change(sk);
 844         }
 845 }
 846
 847 /* Helper function to delete an association. */
 848 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
 849                                 struct sctp_association *asoc)
 850 {
 851         struct sock *sk = asoc->base.sk;
 852
 853         /* If it is a non-temporary association belonging to a TCP-style
 854          * listening socket that is not closed, do not free it so that accept()
 855          * can pick it up later.
 856          */
 857         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
 858             (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
 859                 return;
 860
 861         sctp_unhash_established(asoc);
 862         sctp_association_free(asoc);
 863 }
 864
 865 /*
 866  * ADDIP Section 4.1 ASCONF Chunk Procedures
 867  * A4) Start a T-4 RTO timer, using the RTO value of the selected
 868  * destination address (we use active path instead of primary path just
 869  * because primary path may be inactive.
 870  */
 871 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
 872                                 struct sctp_association *asoc,
 873                                 struct sctp_chunk *chunk)
 874 {
 875         struct sctp_transport *t;
 876
 877         t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
 878         asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
 879         chunk->transport = t;
 880 }
 881
 882 /* Process an incoming Operation Error Chunk. */
 883 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
 884                                    struct sctp_association *asoc,
 885                                    struct sctp_chunk *chunk)
 886 {
 887         struct sctp_errhdr *err_hdr;
 888         struct sctp_ulpevent *ev;
 889
 890         while (chunk->chunk_end > chunk->skb->data) {
 891                 err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
 892
 893                 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
 894                                                      GFP_ATOMIC);
 895                 if (!ev)
 896                         return;
 897
 898                 sctp_ulpq_tail_event(&asoc->ulpq, ev);
 899
 900                 switch (err_hdr->cause) {
 901                 case SCTP_ERROR_UNKNOWN_CHUNK:
 902                 {
 903                         sctp_chunkhdr_t *unk_chunk_hdr;
 904
 905                         unk_chunk_hdr = (sctp_chunkhdr_t *)err_hdr->variable;
 906                         switch (unk_chunk_hdr->type) {
 907                         /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
 908                          * an ERROR chunk reporting that it did not recognized
 909                          * the ASCONF chunk type, the sender of the ASCONF MUST
 910                          * NOT send any further ASCONF chunks and MUST stop its
 911                          * T-4 timer.
 912                          */
 913                         case SCTP_CID_ASCONF:
 914                                 if (asoc->peer.asconf_capable == 0)
 915                                         break;
 916
 917                                 asoc->peer.asconf_capable = 0;
 918                                 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
 919                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
 920                                 break;
 921                         default:
 922                                 break;
 923                         }
 924                         break;
 925                 }
 926                 default:
 927                         break;
 928                 }
 929         }
 930 }
 931
 932 /* Process variable FWDTSN chunk information. */
 933 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
 934                                     struct sctp_chunk *chunk)
 935 {
 936         struct sctp_fwdtsn_skip *skip;
 937         /* Walk through all the skipped SSNs */
 938         sctp_walk_fwdtsn(skip, chunk) {
 939                 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
 940         }
 941 }
 942
 943 /* Helper function to remove the association non-primary peer
 944  * transports.
 945  */
 946 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
 947 {
 948         struct sctp_transport *t;
 949         struct list_head *pos;
 950         struct list_head *temp;
 951
 952         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
 953                 t = list_entry(pos, struct sctp_transport, transports);
 954                 if (!sctp_cmp_addr_exact(&t->ipaddr,
 955                                          &asoc->peer.primary_addr)) {
 956                         sctp_assoc_del_peer(asoc, &t->ipaddr);
 957                 }
 958         }
 959 }
 960
 961 /* Helper function to set sk_err on a 1-1 style socket. */
 962 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
 963 {
 964         struct sock *sk = asoc->base.sk;
 965
 966         if (!sctp_style(sk, UDP))
 967                 sk->sk_err = error;
 968 }
 969
 970 /* Helper function to generate an association change event */
 971 static void sctp_cmd_assoc_change(sctp_cmd_seq_t *commands,
 972                                  struct sctp_association *asoc,
 973                                  u8 state)
 974 {
 975         struct sctp_ulpevent *ev;
 976
 977         ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
 978                                             asoc->c.sinit_num_ostreams,
 979                                             asoc->c.sinit_max_instreams,
 980                                             NULL, GFP_ATOMIC);
 981         if (ev)
 982                 sctp_ulpq_tail_event(&asoc->ulpq, ev);
 983 }
 984
 985 /* Helper function to generate an adaptation indication event */
 986 static void sctp_cmd_adaptation_ind(sctp_cmd_seq_t *commands,
 987                                     struct sctp_association *asoc)
 988 {
 989         struct sctp_ulpevent *ev;
 990
 991         ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
 992
 993         if (ev)
 994                 sctp_ulpq_tail_event(&asoc->ulpq, ev);
 995 }
 996
 997
 998 static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
 999                                     sctp_event_timeout_t timer,
1000                                     char *name)
1001 {
1002         struct sctp_transport *t;
1003
1004         t = asoc->init_last_sent_to;
1005         asoc->init_err_counter++;
1006
1007         if (t->init_sent_count > (asoc->init_cycle + 1)) {
1008                 asoc->timeouts[timer] *= 2;
1009                 if (asoc->timeouts[timer] > asoc->max_init_timeo) {
1010                         asoc->timeouts[timer] = asoc->max_init_timeo;
1011                 }
1012                 asoc->init_cycle++;
1013                 SCTP_DEBUG_PRINTK(
1014                         "T1 %s Timeout adjustment"
1015                         " init_err_counter: %d"
1016                         " cycle: %d"
1017                         " timeout: %ld\n",
1018                         name,
1019                         asoc->init_err_counter,
1020                         asoc->init_cycle,
1021                         asoc->timeouts[timer]);
1022         }
1023
1024 }
1025
1026 /* Send the whole message, chunk by chunk, to the outqueue.
1027  * This way the whole message is queued up and bundling if
1028  * encouraged for small fragments.
1029  */
1030 static int sctp_cmd_send_msg(struct sctp_association *asoc,
1031                                 struct sctp_datamsg *msg)
1032 {
1033         struct sctp_chunk *chunk;
1034         int error = 0;
1035
1036         list_for_each_entry(chunk, &msg->chunks, frag_list) {
1037                 error = sctp_outq_tail(&asoc->outqueue, chunk);
1038                 if (error)
1039                         break;
1040         }
1041
1042         return error;
1043 }
1044
1045
1046 /* Sent the next ASCONF packet currently stored in the association.
1047  * This happens after the ASCONF_ACK was succeffully processed.
1048  */
1049 static void sctp_cmd_send_asconf(struct sctp_association *asoc)
1050 {
1051         struct net *net = sock_net(asoc->base.sk);
1052
1053         /* Send the next asconf chunk from the addip chunk
1054          * queue.
1055          */
1056         if (!list_empty(&asoc->addip_chunk_list)) {
1057                 struct list_head *entry = asoc->addip_chunk_list.next;
1058                 struct sctp_chunk *asconf = list_entry(entry,
1059                                                 struct sctp_chunk, list);
1060                 list_del_init(entry);
1061
1062                 /* Hold the chunk until an ASCONF_ACK is received. */
1063                 sctp_chunk_hold(asconf);
1064                 if (sctp_primitive_ASCONF(net, asoc, asconf))
1065                         sctp_chunk_free(asconf);
1066                 else
1067                         asoc->addip_last_asconf = asconf;
1068         }
1069 }
1070
1071
1072 /* These three macros allow us to pull the debugging code out of the
1073  * main flow of sctp_do_sm() to keep attention focused on the real
1074  * functionality there.
1075  */
1076 #define DEBUG_PRE \
1077         SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
1078                           "ep %p, %s, %s, asoc %p[%s], %s\n", \
1079                           ep, sctp_evttype_tbl[event_type], \
1080                           (*debug_fn)(subtype), asoc, \
1081                           sctp_state_tbl[state], state_fn->name)
1082
1083 #define DEBUG_POST \
1084         SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
1085                           "asoc %p, status: %s\n", \
1086                           asoc, sctp_status_tbl[status])
1087
1088 #define DEBUG_POST_SFX \
1089         SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
1090                           error, asoc, \
1091                           sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
1092                           sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
1093
1094 /*
1095  * This is the master state machine processing function.
1096  *
1097  * If you want to understand all of lksctp, this is a
1098  * good place to start.
1099  */
1100 int sctp_do_sm(struct net *net, sctp_event_t event_type, sctp_subtype_t subtype,
1101                sctp_state_t state,
1102                struct sctp_endpoint *ep,
1103                struct sctp_association *asoc,
1104                void *event_arg,
1105                gfp_t gfp)
1106 {
1107         sctp_cmd_seq_t commands;
1108         const sctp_sm_table_entry_t *state_fn;
1109         sctp_disposition_t status;
1110         int error = 0;
1111         typedef const char *(printfn_t)(sctp_subtype_t);
1112
1113         static printfn_t *table[] = {
1114                 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1115         };
1116         printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
1117
1118         /* Look up the state function, run it, and then process the
1119          * side effects.  These three steps are the heart of lksctp.
1120          */
1121         state_fn = sctp_sm_lookup_event(net, event_type, state, subtype);
1122
1123         sctp_init_cmd_seq(&commands);
1124
1125         DEBUG_PRE;
1126         status = (*state_fn->fn)(net, ep, asoc, subtype, event_arg, &commands);
1127         DEBUG_POST;
1128
1129         error = sctp_side_effects(event_type, subtype, state,
1130                                   ep, asoc, event_arg, status,
1131                                   &commands, gfp);
1132         DEBUG_POST_SFX;
1133
1134         return error;
1135 }
1136
1137 #undef DEBUG_PRE
1138 #undef DEBUG_POST
1139
1140 /*****************************************************************
1141  * This the master state function side effect processing function.
1142  *****************************************************************/
1143 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
1144                              sctp_state_t state,
1145                              struct sctp_endpoint *ep,
1146                              struct sctp_association *asoc,
1147                              void *event_arg,
1148                              sctp_disposition_t status,
1149                              sctp_cmd_seq_t *commands,
1150                              gfp_t gfp)
1151 {
1152         int error;
1153
1154         /* FIXME - Most of the dispositions left today would be categorized
1155          * as "exceptional" dispositions.  For those dispositions, it
1156          * may not be proper to run through any of the commands at all.
1157          * For example, the command interpreter might be run only with
1158          * disposition SCTP_DISPOSITION_CONSUME.
1159          */
1160         if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1161                                                ep, asoc,
1162                                                event_arg, status,
1163                                                commands, gfp)))
1164                 goto bail;
1165
1166         switch (status) {
1167         case SCTP_DISPOSITION_DISCARD:
1168                 SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
1169                                   "event_type %d, event_id %d\n",
1170                                   state, event_type, subtype.chunk);
1171                 break;
1172
1173         case SCTP_DISPOSITION_NOMEM:
1174                 /* We ran out of memory, so we need to discard this
1175                  * packet.
1176                  */
1177                 /* BUG--we should now recover some memory, probably by
1178                  * reneging...
1179                  */
1180                 error = -ENOMEM;
1181                 break;
1182
1183         case SCTP_DISPOSITION_DELETE_TCB:
1184                 /* This should now be a command. */
1185                 break;
1186
1187         case SCTP_DISPOSITION_CONSUME:
1188         case SCTP_DISPOSITION_ABORT:
1189                 /*
1190                  * We should no longer have much work to do here as the
1191                  * real work has been done as explicit commands above.
1192                  */
1193                 break;
1194
1195         case SCTP_DISPOSITION_VIOLATION:
1196                 net_err_ratelimited("protocol violation state %d chunkid %d\n",
1197                                     state, subtype.chunk);
1198                 break;
1199
1200         case SCTP_DISPOSITION_NOT_IMPL:
1201                 pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n",
1202                         state, event_type, subtype.chunk);
1203                 break;
1204
1205         case SCTP_DISPOSITION_BUG:
1206                 pr_err("bug in state %d, event_type %d, event_id %d\n",
1207                        state, event_type, subtype.chunk);
1208                 BUG();
1209                 break;
1210
1211         default:
1212                 pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n",
1213                        status, state, event_type, subtype.chunk);
1214                 BUG();
1215                 break;
1216         }
1217
1218 bail:
1219         return error;
1220 }
1221
1222 /********************************************************************
1223  * 2nd Level Abstractions
1224  ********************************************************************/
1225
1226 /* This is the side-effect interpreter.  */
1227 static int sctp_cmd_interpreter(sctp_event_t event_type,
1228                                 sctp_subtype_t subtype,
1229                                 sctp_state_t state,
1230                                 struct sctp_endpoint *ep,
1231                                 struct sctp_association *asoc,
1232                                 void *event_arg,
1233                                 sctp_disposition_t status,
1234                                 sctp_cmd_seq_t *commands,
1235                                 gfp_t gfp)
1236 {
1237         int error = 0;
1238         int force;
1239         sctp_cmd_t *cmd;
1240         struct sctp_chunk *new_obj;
1241         struct sctp_chunk *chunk = NULL;
1242         struct sctp_packet *packet;
1243         struct timer_list *timer;
1244         unsigned long timeout;
1245         struct sctp_transport *t;
1246         struct sctp_sackhdr sackh;
1247         int local_cork = 0;
1248
1249         if (SCTP_EVENT_T_TIMEOUT != event_type)
1250                 chunk = event_arg;
1251
1252         /* Note:  This whole file is a huge candidate for rework.
1253          * For example, each command could either have its own handler, so
1254          * the loop would look like:
1255          *     while (cmds)
1256          *         cmd->handle(x, y, z)
1257          * --jgrimm
1258          */
1259         while (NULL != (cmd = sctp_next_cmd(commands))) {
1260                 switch (cmd->verb) {
1261                 case SCTP_CMD_NOP:
1262                         /* Do nothing. */
1263                         break;
1264
1265                 case SCTP_CMD_NEW_ASOC:
1266                         /* Register a new association.  */
1267                         if (local_cork) {
1268                                 sctp_outq_uncork(&asoc->outqueue);
1269                                 local_cork = 0;
1270                         }
1271                         asoc = cmd->obj.ptr;
1272                         /* Register with the endpoint.  */
1273                         sctp_endpoint_add_asoc(ep, asoc);
1274                         sctp_hash_established(asoc);
1275                         break;
1276
1277                 case SCTP_CMD_UPDATE_ASSOC:
1278                        sctp_assoc_update(asoc, cmd->obj.ptr);
1279                        break;
1280
1281                 case SCTP_CMD_PURGE_OUTQUEUE:
1282                        sctp_outq_teardown(&asoc->outqueue);
1283                        break;
1284
1285                 case SCTP_CMD_DELETE_TCB:
1286                         if (local_cork) {
1287                                 sctp_outq_uncork(&asoc->outqueue);
1288                                 local_cork = 0;
1289                         }
1290                         /* Delete the current association.  */
1291                         sctp_cmd_delete_tcb(commands, asoc);
1292                         asoc = NULL;
1293                         break;
1294
1295                 case SCTP_CMD_NEW_STATE:
1296                         /* Enter a new state.  */
1297                         sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1298                         break;
1299
1300                 case SCTP_CMD_REPORT_TSN:
1301                         /* Record the arrival of a TSN.  */
1302                         error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1303                                                  cmd->obj.u32, NULL);
1304                         break;
1305
1306                 case SCTP_CMD_REPORT_FWDTSN:
1307                         /* Move the Cumulattive TSN Ack ahead. */
1308                         sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1309
1310                         /* purge the fragmentation queue */
1311                         sctp_ulpq_reasm_flushtsn(&asoc->ulpq, cmd->obj.u32);
1312
1313                         /* Abort any in progress partial delivery. */
1314                         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1315                         break;
1316
1317                 case SCTP_CMD_PROCESS_FWDTSN:
1318                         sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
1319                         break;
1320
1321                 case SCTP_CMD_GEN_SACK:
1322                         /* Generate a Selective ACK.
1323                          * The argument tells us whether to just count
1324                          * the packet and MAYBE generate a SACK, or
1325                          * force a SACK out.
1326                          */
1327                         force = cmd->obj.i32;
1328                         error = sctp_gen_sack(asoc, force, commands);
1329                         break;
1330
1331                 case SCTP_CMD_PROCESS_SACK:
1332                         /* Process an inbound SACK.  */
1333                         error = sctp_cmd_process_sack(commands, asoc,
1334                                                       cmd->obj.ptr);
1335                         break;
1336
1337                 case SCTP_CMD_GEN_INIT_ACK:
1338                         /* Generate an INIT ACK chunk.  */
1339                         new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1340                                                      0);
1341                         if (!new_obj)
1342                                 goto nomem;
1343
1344                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1345                                         SCTP_CHUNK(new_obj));
1346                         break;
1347
1348                 case SCTP_CMD_PEER_INIT:
1349                         /* Process a unified INIT from the peer.
1350                          * Note: Only used during INIT-ACK processing.  If
1351                          * there is an error just return to the outter
1352                          * layer which will bail.
1353                          */
1354                         error = sctp_cmd_process_init(commands, asoc, chunk,
1355                                                       cmd->obj.ptr, gfp);
1356                         break;
1357
1358                 case SCTP_CMD_GEN_COOKIE_ECHO:
1359                         /* Generate a COOKIE ECHO chunk.  */
1360                         new_obj = sctp_make_cookie_echo(asoc, chunk);
1361                         if (!new_obj) {
1362                                 if (cmd->obj.ptr)
1363                                         sctp_chunk_free(cmd->obj.ptr);
1364                                 goto nomem;
1365                         }
1366                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1367                                         SCTP_CHUNK(new_obj));
1368
1369                         /* If there is an ERROR chunk to be sent along with
1370                          * the COOKIE_ECHO, send it, too.
1371                          */
1372                         if (cmd->obj.ptr)
1373                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1374                                                 SCTP_CHUNK(cmd->obj.ptr));
1375
1376                         if (new_obj->transport) {
1377                                 new_obj->transport->init_sent_count++;
1378                                 asoc->init_last_sent_to = new_obj->transport;
1379                         }
1380
1381                         /* FIXME - Eventually come up with a cleaner way to
1382                          * enabling COOKIE-ECHO + DATA bundling during
1383                          * multihoming stale cookie scenarios, the following
1384                          * command plays with asoc->peer.retran_path to
1385                          * avoid the problem of sending the COOKIE-ECHO and
1386                          * DATA in different paths, which could result
1387                          * in the association being ABORTed if the DATA chunk
1388                          * is processed first by the server.  Checking the
1389                          * init error counter simply causes this command
1390                          * to be executed only during failed attempts of
1391                          * association establishment.
1392                          */
1393                         if ((asoc->peer.retran_path !=
1394                              asoc->peer.primary_path) &&
1395                             (asoc->init_err_counter > 0)) {
1396                                 sctp_add_cmd_sf(commands,
1397                                                 SCTP_CMD_FORCE_PRIM_RETRAN,
1398                                                 SCTP_NULL());
1399                         }
1400
1401                         break;
1402
1403                 case SCTP_CMD_GEN_SHUTDOWN:
1404                         /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1405                          * Reset error counts.
1406                          */
1407                         asoc->overall_error_count = 0;
1408
1409                         /* Generate a SHUTDOWN chunk.  */
1410                         new_obj = sctp_make_shutdown(asoc, chunk);
1411                         if (!new_obj)
1412                                 goto nomem;
1413                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1414                                         SCTP_CHUNK(new_obj));
1415                         break;
1416
1417                 case SCTP_CMD_CHUNK_ULP:
1418                         /* Send a chunk to the sockets layer.  */
1419                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1420                                           "chunk_up:", cmd->obj.ptr,
1421                                           "ulpq:", &asoc->ulpq);
1422                         sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1423                                             GFP_ATOMIC);
1424                         break;
1425
1426                 case SCTP_CMD_EVENT_ULP:
1427                         /* Send a notification to the sockets layer.  */
1428                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1429                                           "event_up:",cmd->obj.ptr,
1430                                           "ulpq:",&asoc->ulpq);
1431                         sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1432                         break;
1433
1434                 case SCTP_CMD_REPLY:
1435                         /* If an caller has not already corked, do cork. */
1436                         if (!asoc->outqueue.cork) {
1437                                 sctp_outq_cork(&asoc->outqueue);
1438                                 local_cork = 1;
1439                         }
1440                         /* Send a chunk to our peer.  */
1441                         error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1442                         break;
1443
1444                 case SCTP_CMD_SEND_PKT:
1445                         /* Send a full packet to our peer.  */
1446                         packet = cmd->obj.ptr;
1447                         sctp_packet_transmit(packet);
1448                         sctp_ootb_pkt_free(packet);
1449                         break;
1450
1451                 case SCTP_CMD_T1_RETRAN:
1452                         /* Mark a transport for retransmission.  */
1453                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1454                                         SCTP_RTXR_T1_RTX);
1455                         break;
1456
1457                 case SCTP_CMD_RETRAN:
1458                         /* Mark a transport for retransmission.  */
1459                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1460                                         SCTP_RTXR_T3_RTX);
1461                         break;
1462
1463                 case SCTP_CMD_ECN_CE:
1464                         /* Do delayed CE processing.   */
1465                         sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1466                         break;
1467
1468                 case SCTP_CMD_ECN_ECNE:
1469                         /* Do delayed ECNE processing. */
1470                         new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1471                                                         chunk);
1472                         if (new_obj)
1473                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1474                                                 SCTP_CHUNK(new_obj));
1475                         break;
1476
1477                 case SCTP_CMD_ECN_CWR:
1478                         /* Do delayed CWR processing.  */
1479                         sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1480                         break;
1481
1482                 case SCTP_CMD_SETUP_T2:
1483                         sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1484                         break;
1485
1486                 case SCTP_CMD_TIMER_START_ONCE:
1487                         timer = &asoc->timers[cmd->obj.to];
1488
1489                         if (timer_pending(timer))
1490                                 break;
1491                         /* fall through */
1492
1493                 case SCTP_CMD_TIMER_START:
1494                         timer = &asoc->timers[cmd->obj.to];
1495                         timeout = asoc->timeouts[cmd->obj.to];
1496                         BUG_ON(!timeout);
1497
1498                         timer->expires = jiffies + timeout;
1499                         sctp_association_hold(asoc);
1500                         add_timer(timer);
1501                         break;
1502
1503                 case SCTP_CMD_TIMER_RESTART:
1504                         timer = &asoc->timers[cmd->obj.to];
1505                         timeout = asoc->timeouts[cmd->obj.to];
1506                         if (!mod_timer(timer, jiffies + timeout))
1507                                 sctp_association_hold(asoc);
1508                         break;
1509
1510                 case SCTP_CMD_TIMER_STOP:
1511                         timer = &asoc->timers[cmd->obj.to];
1512                         if (timer_pending(timer) && del_timer(timer))
1513                                 sctp_association_put(asoc);
1514                         break;
1515
1516                 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1517                         chunk = cmd->obj.ptr;
1518                         t = sctp_assoc_choose_alter_transport(asoc,
1519                                                 asoc->init_last_sent_to);
1520                         asoc->init_last_sent_to = t;
1521                         chunk->transport = t;
1522                         t->init_sent_count++;
1523                         /* Set the new transport as primary */
1524                         sctp_assoc_set_primary(asoc, t);
1525                         break;
1526
1527                 case SCTP_CMD_INIT_RESTART:
1528                         /* Do the needed accounting and updates
1529                          * associated with restarting an initialization
1530                          * timer. Only multiply the timeout by two if
1531                          * all transports have been tried at the current
1532                          * timeout.
1533                          */
1534                         sctp_cmd_t1_timer_update(asoc,
1535                                                 SCTP_EVENT_TIMEOUT_T1_INIT,
1536                                                 "INIT");
1537
1538                         sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1539                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1540                         break;
1541
1542                 case SCTP_CMD_COOKIEECHO_RESTART:
1543                         /* Do the needed accounting and updates
1544                          * associated with restarting an initialization
1545                          * timer. Only multiply the timeout by two if
1546                          * all transports have been tried at the current
1547                          * timeout.
1548                          */
1549                         sctp_cmd_t1_timer_update(asoc,
1550                                                 SCTP_EVENT_TIMEOUT_T1_COOKIE,
1551                                                 "COOKIE");
1552
1553                         /* If we've sent any data bundled with
1554                          * COOKIE-ECHO we need to resend.
1555                          */
1556                         list_for_each_entry(t, &asoc->peer.transport_addr_list,
1557                                         transports) {
1558                                 sctp_retransmit_mark(&asoc->outqueue, t,
1559                                             SCTP_RTXR_T1_RTX);
1560                         }
1561
1562                         sctp_add_cmd_sf(commands,
1563                                         SCTP_CMD_TIMER_RESTART,
1564                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1565                         break;
1566
1567                 case SCTP_CMD_INIT_FAILED:
1568                         sctp_cmd_init_failed(commands, asoc, cmd->obj.err);
1569                         break;
1570
1571                 case SCTP_CMD_ASSOC_FAILED:
1572                         sctp_cmd_assoc_failed(commands, asoc, event_type,
1573                                               subtype, chunk, cmd->obj.err);
1574                         break;
1575
1576                 case SCTP_CMD_INIT_COUNTER_INC:
1577                         asoc->init_err_counter++;
1578                         break;
1579
1580                 case SCTP_CMD_INIT_COUNTER_RESET:
1581                         asoc->init_err_counter = 0;
1582                         asoc->init_cycle = 0;
1583                         list_for_each_entry(t, &asoc->peer.transport_addr_list,
1584                                             transports) {
1585                                 t->init_sent_count = 0;
1586                         }
1587                         break;
1588
1589                 case SCTP_CMD_REPORT_DUP:
1590                         sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1591                                              cmd->obj.u32);
1592                         break;
1593
1594                 case SCTP_CMD_REPORT_BAD_TAG:
1595                         SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1596                         break;
1597
1598                 case SCTP_CMD_STRIKE:
1599                         /* Mark one strike against a transport.  */
1600                         sctp_do_8_2_transport_strike(commands, asoc,
1601                                                     cmd->obj.transport, 0);
1602                         break;
1603
1604                 case SCTP_CMD_TRANSPORT_IDLE:
1605                         t = cmd->obj.transport;
1606                         sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1607                         break;
1608
1609                 case SCTP_CMD_TRANSPORT_HB_SENT:
1610                         t = cmd->obj.transport;
1611                         sctp_do_8_2_transport_strike(commands, asoc,
1612                                                      t, 1);
1613                         t->hb_sent = 1;
1614                         break;
1615
1616                 case SCTP_CMD_TRANSPORT_ON:
1617                         t = cmd->obj.transport;
1618                         sctp_cmd_transport_on(commands, asoc, t, chunk);
1619                         break;
1620
1621                 case SCTP_CMD_HB_TIMERS_START:
1622                         sctp_cmd_hb_timers_start(commands, asoc);
1623                         break;
1624
1625                 case SCTP_CMD_HB_TIMER_UPDATE:
1626                         t = cmd->obj.transport;
1627                         sctp_cmd_hb_timer_update(commands, t);
1628                         break;
1629
1630                 case SCTP_CMD_HB_TIMERS_STOP:
1631                         sctp_cmd_hb_timers_stop(commands, asoc);
1632                         break;
1633
1634                 case SCTP_CMD_REPORT_ERROR:
1635                         error = cmd->obj.error;
1636                         break;
1637
1638                 case SCTP_CMD_PROCESS_CTSN:
1639                         /* Dummy up a SACK for processing. */
1640                         sackh.cum_tsn_ack = cmd->obj.be32;
1641                         sackh.a_rwnd = asoc->peer.rwnd +
1642                                         asoc->outqueue.outstanding_bytes;
1643                         sackh.num_gap_ack_blocks = 0;
1644                         sackh.num_dup_tsns = 0;
1645                         chunk->subh.sack_hdr = &sackh;
1646                         sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1647                                         SCTP_CHUNK(chunk));
1648                         break;
1649
1650                 case SCTP_CMD_DISCARD_PACKET:
1651                         /* We need to discard the whole packet.
1652                          * Uncork the queue since there might be
1653                          * responses pending
1654                          */
1655                         chunk->pdiscard = 1;
1656                         if (asoc) {
1657                                 sctp_outq_uncork(&asoc->outqueue);
1658                                 local_cork = 0;
1659                         }
1660                         break;
1661
1662                 case SCTP_CMD_RTO_PENDING:
1663                         t = cmd->obj.transport;
1664                         t->rto_pending = 1;
1665                         break;
1666
1667                 case SCTP_CMD_PART_DELIVER:
1668                         sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1669                                                    GFP_ATOMIC);
1670                         break;
1671
1672                 case SCTP_CMD_RENEGE:
1673                         sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1674                                          GFP_ATOMIC);
1675                         break;
1676
1677                 case SCTP_CMD_SETUP_T4:
1678                         sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1679                         break;
1680
1681                 case SCTP_CMD_PROCESS_OPERR:
1682                         sctp_cmd_process_operr(commands, asoc, chunk);
1683                         break;
1684                 case SCTP_CMD_CLEAR_INIT_TAG:
1685                         asoc->peer.i.init_tag = 0;
1686                         break;
1687                 case SCTP_CMD_DEL_NON_PRIMARY:
1688                         sctp_cmd_del_non_primary(asoc);
1689                         break;
1690                 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1691                         sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1692                         break;
1693                 case SCTP_CMD_FORCE_PRIM_RETRAN:
1694                         t = asoc->peer.retran_path;
1695                         asoc->peer.retran_path = asoc->peer.primary_path;
1696                         error = sctp_outq_uncork(&asoc->outqueue);
1697                         local_cork = 0;
1698                         asoc->peer.retran_path = t;
1699                         break;
1700                 case SCTP_CMD_SET_SK_ERR:
1701                         sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1702                         break;
1703                 case SCTP_CMD_ASSOC_CHANGE:
1704                         sctp_cmd_assoc_change(commands, asoc,
1705                                               cmd->obj.u8);
1706                         break;
1707                 case SCTP_CMD_ADAPTATION_IND:
1708                         sctp_cmd_adaptation_ind(commands, asoc);
1709                         break;
1710
1711                 case SCTP_CMD_ASSOC_SHKEY:
1712                         error = sctp_auth_asoc_init_active_key(asoc,
1713                                                 GFP_ATOMIC);
1714                         break;
1715                 case SCTP_CMD_UPDATE_INITTAG:
1716                         asoc->peer.i.init_tag = cmd->obj.u32;
1717                         break;
1718                 case SCTP_CMD_SEND_MSG:
1719                         if (!asoc->outqueue.cork) {
1720                                 sctp_outq_cork(&asoc->outqueue);
1721                                 local_cork = 1;
1722                         }
1723                         error = sctp_cmd_send_msg(asoc, cmd->obj.msg);
1724                         break;
1725                 case SCTP_CMD_SEND_NEXT_ASCONF:
1726                         sctp_cmd_send_asconf(asoc);
1727                         break;
1728                 case SCTP_CMD_PURGE_ASCONF_QUEUE:
1729                         sctp_asconf_queue_teardown(asoc);
1730                         break;
1731
1732                 case SCTP_CMD_SET_ASOC:
1733                         asoc = cmd->obj.asoc;
1734                         break;
1735
1736                 default:
1737                         pr_warn("Impossible command: %u, %p\n",
1738                                 cmd->verb, cmd->obj.ptr);
1739                         break;
1740                 }
1741
1742                 if (error)
1743                         break;
1744         }
1745
1746 out:
1747         /* If this is in response to a received chunk, wait until
1748          * we are done with the packet to open the queue so that we don't
1749          * send multiple packets in response to a single request.
1750          */
1751         if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1752                 if (chunk->end_of_packet || chunk->singleton)
1753                         error = sctp_outq_uncork(&asoc->outqueue);
1754         } else if (local_cork)
1755                 error = sctp_outq_uncork(&asoc->outqueue);
1756         return error;
1757 nomem:
1758         error = -ENOMEM;
1759         goto out;
1760 }
1761